// Muduo - A reactor-based C++ network library for Linux
// Copyright (c) 2010, Shuo Chen.  All rights reserved.
// http://code.google.com/p/muduo/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
//   * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//   * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//   * Neither the name of Shuo Chen nor the names of other contributors
// may be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


#ifndef CLUSNET_BASE_FIXEDBUFFER_H
#define CLUSNET_BASE_FIXEDBUFFER_H

#include <string>
#include <array>
#include <cstddef>
#include <cstring>

namespace clusnet
{
namespace base
{

template<int SIZE>
class FixedBuffer 
{
    public:
        FixedBuffer(const FixedBuffer<SIZE>& that) = default;
        FixedBuffer(FixedBuffer<SIZE>&& that) = default;
        FixedBuffer<SIZE>& operator= (const FixedBuffer<SIZE>& that) = default;
        FixedBuffer<SIZE>& operator= (FixedBuffer<SIZE>&& that) = default;
        FixedBuffer()
            : cur_(0)
        {
        }
        virtual ~FixedBuffer() = default;

    public:
        void append(const char* buf, size_t len)
        {
            if (avail() >= len)
            {
                std::memcpy(data_.data() + cur_, buf, len);
                cur_ += len;
            }
        }

        size_t length() const { return cur_; }
        size_t avail() const { return  data_.max_size() - cur_; }

        void reset() { cur_ = 0; }
        void bzero() { data_.fill('\0'); }

        typename std::array<char, SIZE>::const_iterator cbegin() const { return data_.cbegin(); }
        typename std::array<char, SIZE>::const_iterator cend() const { return data_.cbegin() + cur_; }

        // used by unit test
        std::string toString() const { return std::string(data_.cbegin(), data_.cbegin() + cur_); }

    private:
        std::array<char, SIZE>  data_;        
        size_t  cur_;
};
}
}

#endif 
